The point of Gaviscon Advance is to create what is called a raft, i.e., a foamy plug at the top of the stomach that keeps the stomach contents in the stomach from two to four hours. I think it does coat the stomach (if I have irritation in my esophagus drinking GA soothes it), but the main point is to plug up the stomach. BTW, there is a difference between GA from the UK and Gaviscon produced in the US. The GA is better, and does not have aluminum. It is available on Amazon.